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Why do we use Subnet mask? What are its uses?

Asked by: Interview Candidate | Asked on: Aug 25th, 2006
Showing Answers 1 - 22 of 22 Answers
Shahzad Siddiqui

Answered On : Aug 26th, 2006

Subnetmask is use to isolate the network ID and Host ID. eg- if an IP is:192.168.0.1 then the default subnet is:255.255.255.0 because it is a C Class Address C Class Add. have 3 network octate and 1 host octate i.e.network ID :192.168.0.0host ID      : 0.0.0.1

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Bashur

Answered On : Aug 29th, 2006

Hi Shahzad Siddiqui,thanx for u r response,u r answer is nice,from,Bashur

  
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Engg Muhammad Waseem

Answered On : Sep 1st, 2006

The main purpose of subnetmasking is to reduce the broadcast domain or in other words to reduce to heavy network traffic.

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The use of subnet mask actually tells you the number of host/terminals that could be used on the same network. It is actually very simple, for eg an IP address 192.168.0.1 with the subnet mask of 255.255.255.0. Just look at the 'ON' bits in this subnet mask (11111111.11111111.11111111.00000000), this clearly indicates that the number of host/terminal that can use the same network are configured and assigned from the last octet. So the number of combination one can drive from the last octect (2x2x2x2x2x2x2x2)= 255 (0-254) which is number of devices that can be used over the network

  
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Rajgopal Medpur

Answered On : Sep 20th, 2006

What is the relation between IP address,Gateway address,Nemask address

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Ram

Answered On : Sep 20th, 2006

Is there is any  relation between subnet and gateway

  
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khadar

Answered On : Oct 10th, 2006

My question is to know how we calculate subnetmask for 3 classes But I know to calculate subnetmask for class c but other then.

  
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Bhavica

Answered On : Nov 23rd, 2006

A subnet allows the flow of network traffic between hosts to be segregated based on a network configuration. By organizing hosts into logical groups, subnetting can improve network security and performance. the most recognizable aspect of subnetting is the subnet mask. Like IP addresses, a subnet mask contains four bytes (32 bits) and is often written using the same "dotted-decimal" notation. For example, a very common subnet mask in its binary representation 11111111 11111111 11111111 00000000 is typically shown in the equivalent, more readable form 255.255.255.0  

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Jai Singh

Answered On : Dec 29th, 2006

Subnet mask is 32 bit long TCP/IP address divided in four equal part.It is used for isolation of network address and host address.

  
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sooraj k r

Answered On : Jun 24th, 2007

Subnetmak is used to identify the network based on the number of bits and the main purpose of subnetmask is to make independent and equal of the network.

  
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naga_u_i2

Answered On : Jul 27th, 2007

Actually Subnet mask is used to Separate Network Bits from Host Bits, For Eg for class C IP address 192.168.0.1 subnet mask is 255.255.255.0so here u can see 255.255.255 mask the Network portion ie., 192.168.0. and leave 8 bits i.e.,[.0] 255 for Host.  So Here we can connect up to 255-1 = 254  Hosts for the 192.168.0 network. Similarly for class B IP address 172.168.0.1 subnet mask is 255.255.0.0so here u can see 255.255 mask the Network portion i.e., 172.168 and leave 16 bits i.e, [0.0.] 255.255 for Host. So here we can connect up to 65,532 hosts for the 172.168.0.1 Network.If u have any doubts can ask me...... thanks

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singhathakur

Answered On : Feb 11th, 2008

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We r useing subnet mask because computers can be understand theer in same Network. And communicate with each other.  

  
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naveemb

Answered On : Sep 27th, 2008

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I don't see the reason why a subnet mask has to be used with default networks like Class A-B-C..., unless you a using subnetting.the reason i say this becasue with the default networks, the ip address itself will help identifying the network and host id.for example 128.45.56.67The very fist octect would tell that this is Class B network.Here N/w is 128 Host is 45.56.67.in the begining when ip address were defined there was no subnetting defined(am i correct here?). And when no subnetting was thought then why did they plan to use a subnet mask?Any body has a answer,then please help me understand this.

  
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Devang

Answered On : Sep 23rd, 2011

We use sub netting for divide a huge network in subnetwork or some user use for some security reasons

  
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prashant

Answered On : Mar 4th, 2012

Sub netting is used to divide an ip address into many ips.
this is must coz we cant give an ip (without sub-netting) to every station. so sub-netting is important

  
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gaurav

Answered On : May 3rd, 2012

As its name suggest it is subnetting a big network in to small pieces to effectively use the network bandwidth for e.g 126.0.0.1 the subnet will be 255.0.0.0 in this case all system which are having starting ip number =126 can communication to any other system on the network.in second case class b network eg-172.168.0.1 the subnet will be 255.255.0.0 here all system which are having first to number as 172.168 can communicate to any other system with in network in third case class C networking eg-192.168.1.1 subnet will be 255.255.255.0 here only those system can communicate to each other which are having first three number as same......

  
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manoj thakur

Answered On : Oct 31st, 2012

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If we are having network of 192.168.0.0 no doubt default subnet mask would be 255.255.255.0
network ip would be 192.168.0.0 and broadcast IP would be 255.255.255.255 but host IDs must fall under 192.168.0.1 to 192.168.255.254 not 0.0.0.1...

  
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Rahul

Answered On : Dec 22nd, 2012

Subnet mask is used to Segment the IP address into HOST and NETWOK.

It used to how many bit is used for Netwok and How many for Host.

  
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nathsambu

Answered On : Dec 22nd, 2012

View all answers by nathsambu

Subnet mask is use only to identify the class of ip address.
Example : c class ip is 192.168.1.1 and subnet mask is 255.255.255.0
In class c, three octal are full i.e. three network part and last one is host part.
Three network part full means we cant change the network part.

  
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Ravinder Kumar

Answered On : Dec 24th, 2012

How is subnetting use in networking and host and subnet id is .i dont understand the subnetting pls deeply and detail wise information send me.

  
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Siva

Answered On : Jun 19th, 2013

Creating multiple indepedentnetworks from a single a network..

  
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rahul

Answered On : Sep 14th, 2013

Subnet mask is used for differentiate the network between network bit and host bit,
by using the subnet mask we know that the how many bit use for network and how many bit use for host

  
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